Equalizing vent valve for vapor heating systems



May 29, 1923. 1,456,688

c. A. FULLER EQUALIZING VENT VALVE FOR VAPOR HEATING SYSTEMS Filed Feb. 27 1922 2 Sheets-Sheet l mari s A TTOR/I/EYS May 29, 1923. V l,456,688

C. A. FULLER EQUALIZING VENT VALVE FOR VAPOR HEATING SYSTEMS Filed Fe 27, 1922 2 SheetsSheet l/JVE/VTOR A TTOR/VEYS Patented May 29, W23.

UNHTED STTES PATENT cornice.

EQUALIZING VENT VALVE FOR VAPOR HEATING SYSTEMS.

Application filed February 27, 1922.

To all whom it may concern:

Be it known that 1, CHARLES A. FULLER, a citizen of the United States, residing at Mount Vernon, county of WVestchester, and State of New York, have invented certain new and useful Improvements in Equalizing Vent Valves for Vapor Heating Systems, of which the following is a specification.

A vapor heating system is characterized by the facts that the return valve of each radiator is thermostatically controlled, and that the air which accumulates in the system when cold is vented through a comparatively large opening in the return pipe, usually located in the basement of the building near the boiler. One of the fundamental ideas of a vapor heating system is that the circulation of steam throughout the entire system will be accomplished by a very low pres-- sure, usually not exceeding. 4 to 6 ounces in. dwelling house installations, this being possible by reason of the fact that the openings through which the air passes are large.

If it were possible to make sure that the steam pressure in the boiler would never exceed the proper amount, say six ounces, all that would be necessary, to allow the air to escape from the return line would be to provide an opening therein, for example, by providing a short, upwardly-standing open ended branch pipe from the return pipe. The air would then escape freely from the return line and the water of condensation would return to the boiler against the low pressure therein which would be overcome by a head, of say, 24 inches of collected water in the return line above the water level in the boiler. Since, however, it is not possible to make sure that the steam pressure in the boiler will never exceed the low value above mentioned, such an opening in the return main would not be satisfactory, since, upon the occurrence of higher steam pressure in the boiler, the water of condensation instead of returning to the boiler, would rise in the return lines, high enough to perhaps flow out this vent opening; or if this vent opening were closed by a float valve, the water of condensation would collect in the return mains instead of returning to the boiler. If the excessive steam pressure, which need not be more than a few pounds, continued for long, the boiler Serial No. 539,381.

would be liable to be thus drained of water to such an extent that damage to it 'would result.

Various means have been suggested for overcoming this difficulty in vapor heating turn line, above the water level in the boiler,

will cause the water in the return line under all conditions to flow back into the boiler.

My invention will be understood from the following description taken in connection with the accompanying drawings in which Figure 1 is an elevation of a steam heating system, having my invention embodied therein, and Fig. 2 is a sectional elevation of my equalizing vent valve adapted for use in the system shown in Fig. 1.

Referring to Fig. 1, the boiler of the heating system is conventionally shown at 5.

From the boiler, steam is carried through the main 6 and branch pipes 7 leading therefrom to the various radiators, only one of which, 8, is shown. vided with a valve 10 by which the admission of steam to the radiator may be controlled, and a thermostatically controlled return line valve 11 which permits air and water to leave the radiator, but which closes automatically by thermostatic action if steam attempts to pass through it. The valves 11 may be of any well known kind and need notbe described in detail since their construction forms no part of the present invention. The valves 11 are connected to branch return pipes such as 13 leading to one or a plurality of main return lines 14 which are connected thru the pipe 15 to the boiler near the bottom thereof through the usual check valve 16. Each return line 14 may be equipped with any well known air vent valve to-permit the escape of air fromthe system. Preferably, however, this vent valve is structurally combined with the Each radiator is proequalizing valve which forms an essential feature of my invention. as hereinafter described.

In order to insure that the water 01' con densation will flow back to the boiler from .the return pipes under all pressure condisist of a weighted or spring b ased check valve which serves at all times to admit enough steam to the return pipe 14 to keep the pressure in that pipe, up to. say onehalf poundbelow the pressure in the boiler. By arranging the piping so that the head of the water-which may stand in the return pipe 15 above'the boiler level, is sufiicient to exceed somewhat the di'llerence between the pressure in the return, pipe 14 and the boiler, the return o't' the water of condensation to the boiler is assured. The air venting portion of the valve 20 may be, and preferably is, of the thermostatically and float controlled type and is so shown and described.

In Figure 2 is shown a preferred form of my equalizing vent valve. This valve has a main casing 22 provided withan inlet 23 and an outlet 24 separated from one another by a partition wall 26 in which is located a horizontally arranged valve seat 28 which may be in the form of a removable bronze or brass sleeve. Cooperating with the valve seat 28 is a movable valve member which may be of the form shown, and which has extending from it a stem 31. The stem 31 extends upwardly through a hole 32 in a guide 33 which is preferably integral with a cap member 34' threaded on to the upper portion of the casing 22. The stem 31 thus acts as a guide for the valve 30. In order to permit regulation of the pressure which will be required to lift the valve member 30, the latter is provided with a plurality of removable weights, such as and 36, which surround the stem 31.

The member 34'preterably serves, not only to support the guide 33. but also to support the air ventvalve structure. For this'purpose the member 34 may he provided with a plurality of openings 36 which permit air and steam to pass upwardly into a cylindrical shell 38 which at the bottom screws into the member 34,-and has a cap 40 which screws on to the top of the shell 38. The vent valve structure may be of any suitable kind. As shown, it contains a float 41 which may be of the form shown with a slotted base wall which permits free passage of air and steam from the main casing through the openings 36 and upwardly within the shell 38. At its top, the float 41 is provided with a hemispherical valve member 43 which cooperates with a hole 44 through the cap 40 and prevents escape of water through that hole when the float 41 is lifted. The hole 44 connects with another shell 46 having a vent 47 which is thermostatically controlled in any well known manner. The shells 38 and 46 together form what may be called an auxiliary casing for the vent valve structure. and the vent47 from the auxiliary casing, which is normally maintained open, is closed when steam reaches the shell 46, by means of a thermostatic element of well known form .such as one characterized by a pluralitv of containers 48 partially filled with some volatile fluid and having diaphragms which expand outwardly under the pressure of the volatile fluid when the latter is heated, and increase the length of the unit thereby bringing the valve member 50 into engagement with the vent opening 47 and closing the latter.

lt will be understood that when my equalizing vent valve is installed the weight of the movable valve member is adjusted by adding or removing weights 3'5 and 36 so that the pressure required to open the valve is approximately equal to the diference in pressure which it is desired to maintain between the boiler and the return line. Assuming that this pressure difference is -3 lb. and that in making the installation it is possible to locate the return pipe 14 so that the distance a from the water level in the boiler up to the return. pipe 14 is 24 or. more, the system will operate. in the following manner.

Under normal conditions, that is, when the pressure in the boiler does not exceed 4 to (3 ounces, the valve member 30, will remain on its valve seat 28, and no steam will be admitted through the pipes 1'7 and 18 to the return line 14: and the pressure in the latter will be substantially equal to atmospheric pressure because the air vent will be open. Under this condition, air driven into the return lines will escape freely through the air vent and the water of condensation from the radiators will return to the boiler, against the low pressure in the latter, by reason of a low head of water which will accumulate in the return line above the level of the water in the boiler.

It. however. the pressure in the boiler rises higher than the normal value and exceeds the pressure for which the equalizing valve is adjusted, this boiler pressure will cause the valve member 30 to rise from its seat 28 and allow steam to flow through and up into msaeee the auxiliary casing through the openings 36, around the float 41, through the opening 44 and around the thermostatic element which controls the vent 47. Under the heating influence of the steam, the thermostatic element will immediately expand, thereby causing the valve member to close the vent opening 47. With the vent opening 47 closed, escape of air or steam through it will be prevented and the pressure in the return line 14: and in the branches 13 leading thereto will rise as the pressure in the boiler rises. The pressure in the return lines, however, will at all times be slightly below the pressure in the boiler due to the reducing effect of the weighted valve member 30. T is difference in the pressures in the boiler and in the return line will be determined in amount by the weight of the movable valve member 30, which, as hereinbefore mentioned, can be adjusted by adding or removing weights 35 and 36. As above stated, it is assumed in this description that the weight of the valve member 30 is also so adjusted that a difference of 9; lb. will be maintained between the pressures in the boiler and in the return line. Obviously, as long as the excess pressure continues in the boiler, the equalizing valve will serve to maintain the pressure in the return line up to within lb. below the pressure in the boiler. Under this condition, water of condensation in the return line will flow back to the boiler as under normal conditions, owing to the fact that the excess of pressure in the boiler over the pressure in the return line will be overcome by a head I) of water which can accumulate in the return line above the level of the water in the boiler. As the pressure in the'boiler again falls to normal, the equalizing valve remains closed, and the pressurein the return line drops to about atmospheric pressure by reason of the cooling of the thermostatic unit and the consequent opening of the air vent 47. Under these circumstances, it will not be possiblefor the water to rise in the return line 15 more than a certain distance 6 above the water line of the boiler, because of the rise in pressure in the return line 14 which is accomplished by the compression of the air in this line by steam flowing through the equalizing valve 20. Therefore, the return line 14 and the branch return line 13, can never be flooded by the water of condensation and thus cause the boiler water line to be lowered below a safe level.

By combining the equalizing valve and the air vent valve in one structure, the prompt closing of the vent opening when steam passes through the equalizing valve 1s assured, and the amount of steam necessary to accomplish the desired equalization of pressure is reduced to a negligible quantity, and the efliciency of the system is thereby maintained. Furthermore, by combining the equalizing and vent valves in one structure, the amount of labor and material neces sary for the proper installation of the system is reduced to a minimum and the possibility of the apparatus being improperly installed is lessened.

While I have shown one structure in which my invention may be embodied, it is to be understood that this is merely illustrative and that in the appended claims I intend .to cover the invention in whatever equivalent structures it may be embodied.

Having described my invention, I claim:

1. An equalizing vent valve for use in a vapor heating system comprising a main casing containing a check valve adapted to open only when the pressure on one side exceeds the pressure on the other side by a substantial amount, an auxiliary casing having a vent opening therein mounted upon said main casing, the inside of said auxiliary casing being in direct and free communication with the outlet side of said main casing, a normally open vent valve controlling the vent in said auxiliary casing, and means located in said casing and responsive to the heat of steam passing through said check valve for closing said vent valve promptly when said check valve opens and allows steam to pass therethru.

2. An equalizing vent valve for use in a vapor heating system, comprising a main casing provided with an inlet and outlet separated from one another by a partition wall in which is located a horizontally arranged valve seat, a movable check valve member co-operating with said valve seat and having an upwardly extending stem, a cap member removably attached to the top of said main casing and having a guide co-operating with said valve stem, said cap member being provided with openings therethru, an auxiliary casing having a vent opening therein mounted on said cap member and covering the openings in the latter. a normally open vent valve member controlling the vent in said auxiliary casing, and means located in said auxiliary casing and responsive to the heat of steam passing through said check valve for closing said vent valve promptly when said check valve opens and allows steam to pass therethru. v

In testimony whereof I have afiixed my signature to this specification.

CHAS. A. FULLER. 

